句子结构简洁，Boasting about... 是动名词短语作主语，is a mistake 是主系表结构，直接点明行为性质。
Understanding that moderate spending is true frugality defines a person who is truly good at saving; mistaking extreme stinginess for frugality is foolish, as it often leads to even greater expenditures. Understanding that appropriate labor is true leisure defines a person who is truly good at relaxing; mistaking pure laziness and comfort for rest is delusional, ultimately resulting in more work. Understanding that enduring moderate hardships leads to true happiness defines a person who is truly good at finding joy; seeking only simple pleasure is foolish and leads to greater suffering. Understanding that keeping channels open is the true way to prevent blockage defines a person who is truly good at managing flow; relying solely on prevention is foolish, and once a breach occurs, the consequences can be uncontrollable.
If you realize your thoughts are wandering, immediately rein them in; if you know you are sick, seek treatment. Boasting about your own strengths is a mistake, and envying others' strengths reveals your own weaknesses.
懂得适当的花销才是真节俭，这才是善于节俭的人；若将一味吝啬小气视为节俭，则是愚笨之举，其花费往往反而加倍。懂得适当的劳动才是真悠闲，这才是善于悠闲的人；若将一味懒惰安逸视为休息，则是糊涂之见，最终付出的劳动只会更多。懂得适当吃苦才是真快乐，这才是善于快乐的人；若只知单纯享乐，则是愚蠢，只会遭受更多苦难。懂得疏通才是真防塞，这才是善于疏堵的人；若一味防范堵塞，则是愚蠢，一旦疏通，后果往往不可收拾。
觉察到心思放纵，便要立即收回；知道自己生病，就要用药治疗。夸耀自己的优点便是错误，嫉妒别人的长处恰恰暴露了自己的短处。
"If the mind becomes full, one becomes arrogant and conceiving of self-importance."
"A truly learned person is humble and does not lecture everyone."
"No matter how successful one becomes, one must remain humble."
"Humility is to excellence as shading is to a picture."
"Heavy ears of grain always bow their heads."